CN113974563B

CN113974563B - Hardness tester and hardness measuring method

Info

Publication number: CN113974563B
Application number: CN202111292977.1A
Authority: CN
Inventors: 佐野佑子; 神鸟明彦; 冲本满男; 安藤茂光; 渡边光信
Original assignee: Maxell Ltd
Current assignee: Maxell Ltd
Priority date: 2016-12-19
Filing date: 2017-12-15
Publication date: 2024-09-27
Anticipated expiration: 2037-12-15
Also published as: US11337641B2; JP6829065B2; CN109891210A; CN109891210B; WO2018116968A1; CN113974563A; JP2018100848A; US11678837B2; US20220240839A1; US20190313962A1

Abstract

The invention aims to provide a hardness meter which can stably calculate hardness irrespective of compression strength. The hardness tester of the present invention is characterized by comprising: a movable part that can be continuously pressed against a measurement object; a sensor that outputs an output signal reflecting a reaction force of a portion of the object to be measured, the portion being in contact with the movable portion; a power mechanism for moving the movable portion in a piston manner; and a hardness estimating unit that estimates the hardness of the object to be measured based on an alternating current component of the output signal generated by the piston movement of the movable unit.

Description

Hardness tester and hardness measuring method

The application is a divisional application of the patent application of the same name with the application number 201780067016.6 and the application date 2017.12.15.

Technical Field

The present invention relates to a durometer for estimating hardness of an object.

Background

In many cases, the hardness of the object to be measured is beneficial. For example, in the medical and cosmetic fields, it is desired to measure the hardness of the human body. In the medical field, it is possible to determine ulcers of the skin of the support surface due to bedridden patients in the same posture over a long period of time, edema of the skin due to changes in organs, scleroderma symptoms, and the like by measuring the hardness of a predetermined portion. In departments such as acupuncture and orthopedics department, the device can also be used for judging the effect of softening muscles caused by acupuncture and massage treatment. In the cosmetic field, the degree of progression of a disease, the effect of a drug treatment, and the like can be determined by measuring the hardness of a predetermined portion.

In order to cope with such a use, a measuring instrument called a durometer (durometer) has been conventionally used, which uses the degree of sagging of an object when the object is pressed (pressed) with a certain force as an index of hardness. Further, a tactile sensor has been developed that acquires information on a change in resonance state when a mechanical vibration portion is in contact with an object, and outputs the information as hardness information of the object (see patent document 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 10-062328

Disclosure of Invention

Technical problem to be solved by the invention

The above-mentioned hardness tester has a problem in that the measurement result, that is, the degree of sagging of the object changes according to the force with which the person presses the object. That is, even if the same object is used, the hardness calculated when the object is lightly pressed and pressed with force is different. For this reason, the present invention solves this problem by using a durometer provided with a mechanism for actively and periodically moving a pressure sensor in addition to the mechanism provided with the durometer.

Technical means for solving the problems

One aspect of the present invention is a hardness tester comprising: a movable part that can be continuously pressed against a measurement object; a sensor that outputs an output signal reflecting a reaction force of a portion of the object to be measured, the portion being in contact with the movable portion; a power mechanism for moving the movable portion in a piston manner; and a hardness estimating unit that estimates the hardness of the object to be measured based on an alternating current component of the output signal generated by the piston movement of the movable unit.

A hardness measurement method according to another aspect of the present invention includes: a first step of vibrating the movable part; a second step of acquiring a sensing signal, wherein the sensing signal is caused by a reaction force from the object to be measured when the movable portion is brought into contact with the object to be measured; a third step of acquiring an alternating component of the sensing signal; and a fourth step of estimating the hardness of the object to be measured based on the amplitude of the alternating current component.

Effects of the invention

With the present invention, in the durometer, the hardness can be estimated from only the output value of the pressure sensor regardless of the pressing strength of the operator. The technical problems, features, and technical effects other than those described above will be apparent from the following description of the embodiments.

Drawings

Fig. 1 is a block diagram showing the overall structure of a living body durometer.

Fig. 2 is a perspective explanatory view of a structural example of the measuring device (gun type).

Fig. 3 is a perspective explanatory view of a configuration example of the measuring device (T-shape).

Fig. 4 is a schematic illustration of the working principle of the measuring device.

Fig. 5 is a schematic diagram of the voltage waveform of the magnetic sensor of the biological sclerometer.

Fig. 6 is a schematic diagram of converting a voltage waveform of a magnetic sensor of a biological sclerometer into a force.

Fig. 7 is a schematic explanatory diagram of the hardness estimation method.

Fig. 8 is a schematic diagram of the calculation of hardness from the output waveform of the living body hardness meter by fixing the dc component.

Fig. 9 is a schematic diagram of the calculation of hardness by fixing an ac component based on the output waveform of the living body hardness meter.

Fig. 10 is a graph showing the hardness estimation result.

Fig. 11 is an example of a flowchart showing the entire flow of the processing performed by the living body durometer.

Fig. 12 is a diagram of a subject registration screen.

Fig. 13 is a diagram showing the deduced hardness and hardness distribution map on the result display screen.

Fig. 14A is a table diagram showing an example of a correspondence table of the embodiment.

Fig. 14B is a table diagram showing another example of the correspondence table of the embodiment.

Fig. 15 is a graph showing hardness distribution diagrams before and after treatment on a result display screen.

Fig. 16 is a schematic diagram showing a measuring device for performing position estimation.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings illustrate specific embodiments in accordance with the principles of the invention, but they are used only to understand the invention and should not be used to limit the invention. In addition, structures common to the figures may be given the same reference numerals.

The following examples relate to a technique for calculating the hardness of a measurement object. The hardness is an index indicating the degree of hardness of the object to be measured, and represents elasticity. Hereinafter, a living body such as a human body will be described as an example of a measurement object, but the present invention is not limited thereto. For example, the hardness tester of the following example may be applied to objects other than living bodies.

Fig. 1 is an overall configuration diagram of a living body durometer. The living body durometer 1000 includes a measurement device 1 and a durometer calculation device 2. The measuring device 1 of fig. 1 is not illustrated in the partial structure as compared with the measuring device 1 of fig. 2,3, and 4. The structure and operation principle of the measuring device 1 will now be described with reference to fig. 2,3 and 4.

Fig. 2 shows a structure of one example of the measuring apparatus 1. The measuring device 1 includes a main body portion 14, a movable portion 15, a spring 13 (elastic body), a battery 16, a motor 17, and an up-and-down movable portion 18, wherein the main body portion 14 includes a receiving coil 11 (magnetic field detecting unit), and the movable portion 15 includes a transmitting coil 12 (magnetic field generating unit). The motor 17 is driven by the battery 16, and can move the up-and-down movable portion 18 in a piston manner, for example, by a crank mechanism. The receiving coil 11 and the transmitting coil 12 are collectively referred to as a magnetic sensor 19. The magnetic sensor 19 outputs reaction force information corresponding to the reaction force of the portion of the object 150 contacting the movable portion 15.

The contact portion 20 of the movable portion 15 is a portion that presses the object to be measured 150 to recess the object to be measured 150 when measuring (calculating) the hardness, and is a contact surface between the movable portion and the object. Wherein the main body portion 14 and the movable portion 15 have rigidity. The measurement object 150 is, for example, a torso of a human body or another object to be measured for hardness.

The magnetic sensor 19 outputs information of a voltage corresponding to the magnitude of the reaction force of the measurement object 150, and the reaction force of the measurement object 150 corresponds to the pressure applied to the measurement object 150 by the measurement device 1. Accordingly, the receiving coil 11 and the transmitting coil 12 are arranged in a manner opposed to each other. A spring 13 (see fig. 2) having a spring constant K' (known) is disposed between the main body 14 and the movable portion 15.

The spring 13 may be replaced with a spring having a thicker wire diameter of the same shape. Thus, the hardness of the deep position of the object can be measured. The prior art only measures the hardness of the skin surface, and has the problem that information of the deep layer of the skin cannot be obtained. By adopting the structure of the present invention, not only the skin surface but also the hardness of subcutaneous tissue, muscle, etc. up to the deep layer of the skin can be measured.

Fig. 3 shows a structure of another example of the measuring apparatus 1. In fig. 2, the entire housing has an L-shape, but a T-shape or a pencil-shape may be employed for easy holding by the operator. Fig. 3 shows an example of a T-shape. The same reference numerals are given to the structures in common with fig. 2 in fig. 3. The position measuring device 3 including the three-axis receiving coil 301 and the transmitting coil 302 will be described later.

The operation of the magnetic sensor 19 and peripheral components will be described with reference to fig. 4. First, the ac oscillation source 31 generates an ac voltage having a specific frequency (for example, 20 kHz). The ac voltage is converted into an ac current having a specific frequency by the amplifier 32, and the converted ac current flows to the transmitting coil 12. The alternating current flowing in the transmitting coil 12 generates a magnetic field that generates an induced electromotive force in the receiving coil 11.

The induced electromotive force generates an ac current (the same frequency as the ac voltage generated by the ac oscillation source 31) in the receiving coil 11, the ac current is amplified by the preamplifier 33, and the amplified signal is input to the detection circuit 34. The detection circuit 34 detects the amplified signal based on the specific frequency or 2 times the frequency generated by the ac oscillation source 31. For this purpose, the output of the ac oscillation source 31 is introduced as a reference signal 35 to a reference signal input terminal of the detection circuit 34. In addition, an operation mode using a full-wave rectifier circuit may be employed instead of the detector circuit 34. The information (output signal) of the voltage from the detection circuit 34 (or the rectifying circuit) is passed through the low-pass filter 36 and then introduced into the driving circuit 21 (see fig. 1) of the hardness calculation device 2.

The measurement object 150 can be modeled as a spring 37 (a) having a spring constant K and a buffer (damper) 37 (b) having a damping coefficient G. The magnetic sensor 19 composed of the receiving coil 11 and the transmitting coil 12 is pressed against the measurement object 150. The spring constant K 'of the spring 13 and the spring constant K of the measurement object 150 preferably have a relationship of K' > K. This is because otherwise, when the body 14 is pressed, the body 14 may come into contact with the object 150 at the contact portion 20.

Next, referring back to fig. 1, the hardness calculation device 2 will be described. The hardness calculation device 2 is a computer device. The hardness calculation device 2 includes a drive circuit 21, a microprocessor 23, a storage unit 24, a sound generation unit 25, a display unit 26, a power supply unit 27, an input unit 28, and a position estimation drive circuit 29.

The microprocessor 23 is implemented, for example, by a CPU (Central Processing Unit: central processing unit). The microprocessor 23 includes a voltage waveform generating section 231, an abnormal waveform detecting section 232, a voltage-pressure converting section 233, a hardness estimating section 234, a judging section 235, and a position estimating section 236. The processing unit of the microprocessor 23 can be realized by various programs. For example, various programs stored in the storage unit 24 are developed into a memory (not shown) of the hardness calculation device 2. The microprocessor 23 executes a program loaded into the memory to perform predetermined processing and calculation. The processing contents of each processing unit of the microprocessor 23 will be described below.

The voltage waveform generating unit 231 generates waveform information of the output voltage of the magnetic sensor obtained from the drive circuit 21. An example of the waveform of the output voltage of the magnetic sensor will be described in detail later with reference to fig. 5.

The abnormal waveform detecting unit 232 detects an abnormal waveform in the case of improper compression, for example, in the case of weak compression or strong compression, or in the case of inclination of the compression direction with respect to the object surface. In the hardness estimation, the pressing strength of the operator needs to fall within a proper range, and the abnormal waveform detection unit 232 is intended to remove the waveform when the hardness deviates from the proper range.

As a method for detecting an abnormal waveform, it can be determined that an abnormality has occurred, on the condition that the magnitude of the dc component of the output signal does not fall within a certain range. Or can be determined to be an abnormal waveform based on the upper limit and the lower limit of the ac component where the output signal cannot be detected. The hardness is detected based on the ac component of the output signal in a range where such abnormal waveform is not detected.

The voltage-pressure conversion unit 233 converts the output voltage of the magnetic sensor into pressure information. The output voltage of the magnetic sensor varies with the distance between the receiving coil 11 and the transmitting coil 12 of fig. 2. And the distance between these 2 coils is equal to the length of the spring 13. The reaction force acting on the spring can be calculated using the distance the spring 13 shortens from the free length and the spring constant of the spring 13 according to hooke's law. The output voltage of the magnetic sensor is converted into pressure information based on these relationships. The conversion of the output voltage of the magnetic sensor into pressure information will be described in detail later with reference to fig. 6 and 7.

Specifically, at a prescribed 2 inter-coil distance, the magnetic flux is calculated as follows. Let ds1 be the line differential element on the receiving coil 11 and ds2 be the line differential element on the transmitting coil 12. Let ds2 as viewed from ds1 have a position vector r. At this time, the mutual inductance M ₁₂ of the receiving coil 11 and the transmitting coil 12 is calculated by the following formula (Neumann formula). Mu is magnetic permeability.

(1)

Assuming that a current I flows in the receiving coil 11 and the number of turns of the receiving coil 11 is N, the magnetic flux Φ in the transmitting coil 12 can be calculated using the following equation of M ₁₂.

(2)

φ＝NM₁₂I

In the same manner, each magnetic flux Φ in which the distance between 2 coils is changed stepwise by a predetermined distance is calculated. The magnetic flux phi is linearly related to the output voltage of the magnetic sensor. Therefore, from these data, a conversion curve of 2 inter-coil distances and the output voltage of the magnetic sensor can be generated. Next, the distance between the coils was subtracted from the free length of the spring 13 by 2, and the displacement of the spring 13 was obtained. The reaction force can be obtained by multiplying the displacement amount by the spring constant of the spring 13. By the above method, a conversion curve of the output voltage of the magnetic sensor and the reaction force can be generated.

< Method of estimating hardness >

The hardness estimation unit 234 will be described with reference to fig. 5 to 10.

Fig. 5 is an output waveform of the magnetic sensor 19, in which the horizontal axis represents time (seconds) and the vertical axis represents output voltage (V). The operator presses the biological hardness meter 1000 against the measurement object 150 in a little by little, and obtains a waveform of the output voltage of the magnetic sensor 19 as shown in fig. 5. For simplifying the conditions, the hardness of the object 150 to be measured is kept constant regardless of the depth, that is, the hardness is uniform (the same applies to fig. 6 to 9). Here, the slow variation due to hand pressure after the frequency component of the motor 17 is removed is referred to as a direct current component V _D, and the amplitude of the rapid variation having the frequency component of the motor 17 is referred to as an alternating current component V _A. It is understood that, when the pressure is applied little by little, the dc component V _D becomes larger, and the ac component V _A becomes larger gradually. This is because the distance between the receiving coil 11 and the transmitting coil 12 decreases with compression, the voltage of the magnetic sensor 19 increases exponentially. The extraction of the dc component and the ac component may be performed using a known analog or digital frequency filter.

Fig. 6 is a waveform obtained by converting the waveform of the output voltage of the magnetic sensor 19 into a waveform of pressure by the voltage-pressure conversion unit 233. The horizontal axis represents time (seconds) as in fig. 5, and the vertical axis represents the converted pressure (N). In the pressure waveform, when the pressure is applied little by little, the dc component F _D increases, but the amplitude of the ac component F _AC is always constant. The ac component is kept constant unlike the output voltage of the magnetic sensor of fig. 5. The estimated hardness can be obtained based on the ac component F _AC.

In order to obtain the actual hardness, a plurality of objects having a known hardness are prepared, and the amplitude of the ac component F _AC is obtained by measuring the object with the living body durometer 1000. This gives a table of known hardness versus ac component F _AC. Thus, after the object whose hardness is unknown is measured, the ac component F _AC is obtained, and can be converted into the hardness based on the correspondence table. The conversion formula is obtained by interpolating the data of the correspondence table by linear interpolation, spline interpolation, or the like, and even the ac component F _AC not in the correspondence table can be converted into the hardness. The correspondence table may be created and constructed in advance as a database, and stored in the storage unit 24 as the database 1001, for example. The hardness estimation unit 234 converts the pressure obtained from the voltage-pressure conversion unit 233 into hardness by referring to the database 1001.

Fig. 7 is a schematic explanatory diagram of the hardness estimation method. Here, the reason why the ac component F _AC is regarded as the estimated hardness in the pressure waveform of fig. 6 will be described with reference to fig. 7. When the operator presses the measurement object with a constant force F ₀, the motor 17 further imparts a small periodic variation in the amplitude a _C. Assuming that the pressing amount is D, the amount of change (change width) of the force due to the periodic variation of the amplitude a _C is Δf, in this case, according to hooke's law, there is D: a _C＝F₀: the relationship of Δf holds.

This means that Δf varies with the hardness of the measurement object. That is, since the amplitude a _C is constant, when the object to be measured 150 is soft (the spring constant K of the object to be measured is small), the press-in amount D is large, and thus the change Δf of the force generated by the amplitude a _C of the motor 17 corresponding to F ₀ is small. On the other hand, when the measurement object is hard (the spring constant K of the measurement object is large), the press-in amount D is small, and thus the change Δf of the force generated by the amplitude a _C of the motor 17 corresponding to F ₀ is large.

The above is described below using the calculation formula. Assuming that the spring constant of the measurement object 150 is K, the amount of pushing D [ mm ] when the operator presses the living body durometer 1000 with a certain force F is equal to or smaller according to hooke's law.

F＝KD

At this time, the contact portion 20 is moved up and down by the motor 17 at a predetermined amplitude a _C. At this time, when the operator presses by hand with a predetermined force f=f _D＝KD_D, the force when the motor 17 reaches the highest position (D _D-A_C) is as follows.

F_U＝K(D_D-A_C)＝F-KA_C

At this time, when the operator presses with a predetermined force f=f _D＝KD_D, the force when the motor 17 reaches the lowest position (D _D+A_C) is as follows.

F_L＝K(D_D+A_C)＝F+KA_C

The difference F _AC (=force ac component) between the forces when the motor 17 is in the highest position and the lowest position is as follows.

F_AC＝F_L-F_U＝2KA_C

Since a _C is constant, F _AC is proportional to the spring constant K of the object. From this, it is clear that F _AC increases as the object becomes harder. As can be seen from this calculation formula, the ac component F _AC of the force is always constant regardless of the compression strength (dc component of the force) as long as the object has the same hardness.

A case where the hardness is estimated by directly using the output voltage of the magnetic sensor as the force sensor will be described with reference to fig. 8. In this case, the voltage-pressure conversion unit 233 is omitted, and the output voltage of the magnetic sensor 19 is directly used as the pressure. In this case, as shown in the waveform of fig. 8, in the magnetic sensor, the ac component V _A increases with an increase in the dc component V _D (i.e., with an increase in the compression strength). This is different from the case where the voltage-pressure conversion unit 233 is used, in which the ac component of the force is always constant regardless of the dc component of the force (compression strength).

As a cause for not keeping the ac component constant as described above, there is a cause in which the relationship between the output voltage of the magnetic sensor and the force is not proportional. Since the 2 inter-coil distances between the transmitting coil 12 and the receiving coil 11 inside the durometer are equal to the length of the spring 13 inside the durometer, the 2 inter-coil distances are linear with force according to hooke's law. On the other hand, the magnitude of the magnetic flux does not have a linear relationship with the 2 inter-coil distances between the transmitting coil 12 and the receiving coil 11, but has a nonlinear relationship in which the closer the 2 coils are, the greater the magnetic flux becomes. Therefore, the force and the magnetic flux also have a nonlinear relationship, and the ac component increases with the increase in the compression strength.

Here, when the output voltage of the magnetic sensor is used as it is as pressure without using the voltage-pressure conversion unit 233, the ac component V _AC of the voltage when the dc component V _D of the voltage is fixed to the constant value V _DC is used as the estimated hardness. In this way, the hardness estimation can be performed without being affected by the nonlinear characteristics between the magnitude of the magnetic flux and the distance between 2 coils.

Specifically, the database 1001 of the storage unit 24 stores a table of the amplitude and hardness of V _AC when the dc component V _D is fixed to the predetermined value V _DC. The dc component V _D is monitored during measurement, and the amplitude of the ac component V _AC when the dc component is the predetermined value V _DC is obtained. Then, the hardness corresponding to the amplitude is obtained by referring to the correspondence table.

An example of a method for determining the constant value V _DC will be described with reference to fig. 8. When the measuring device 1 is gradually applied to the object 150 and gradually pressed, the ac component cannot be obtained completely in the range (a) of the state where the durometer lightly touches the object 150 (the state where the dc component V _D of the voltage is small). On the other hand, in the range (C), which is a state where the durometer presses into the measurement object and saturation occurs, the object becomes hard like a rigid body, and thus an accurate value of the ac component cannot be obtained. That is, the constant value V _DC is set to a voltage in the range (B) between the two extreme states, so that the ac component can be obtained appropriately in the voltage waveform. However, since the spring constant of the spring 13 inside the measuring device 1 is dependent, once the spring is replaced, the certain value V _DC needs to be determined again.

Fig. 9 shows another example. In the same way as in fig. 8, as shown in fig. 9, the estimated hardness may be calculated from the dc component V _DC of the voltage when the ac component V _A of the voltage is fixed to a constant value V _AC. The method also enables hardness estimation without being affected by the nonlinear characteristics between the magnitude of the magnetic flux and the distance between 2 coils. The dc component V _AC of the voltage may be set to a dc component of the voltage in the range (B) between the two extreme states of the state (a) of light contact and the state (C) of strong pressing and saturation, as in the setting method of V _DC described above.

Fig. 8 and 9 illustrate a method of estimating hardness based on an ac component when the dc component is fixed or a dc component when the ac component is fixed without using the voltage-pressure conversion unit 233. However, even when the voltage-pressure conversion unit 233 is provided, depending on the property of the measurement object, the ac component of the force may not always be constant. In this case, the hardness push algorithm of fig. 8 and 9 can be used to advantage.

Fig. 7 illustrates the object whose hardness is estimated by simplifying the object to have the same characteristics as the spring, but it is practically conceivable to measure the biological tissue such as skin, muscle, fat, etc. of the human body. The spring can accurately obey hooke's law, and its spring constant is a certain value (fixed value) regardless of the pressing strength. However, it is known that biological tissue has a property that a spring constant (hardness) increases with strong compression. Therefore, in the case of measuring the biological tissue, even after converting the output voltage of the magnetic sensor into a force, the ac component F _D may not be kept constant but may increase as the compression becomes stronger, as shown in fig. 6. For this reason, even when the voltage-pressure conversion unit 233 is used, the hardness can be estimated based on the ac component when the dc component is fixed (see fig. 8) or the dc component when the ac component is fixed (see fig. 9). In addition, when the spring constant (hardness) varies depending on the compression strength, fixed values of several ac components or dc components may be set.

Fig. 10 shows the result of estimating the hardness by the method of fig. 9 using the magnetic sensor 19 but without using the voltage-pressure conversion unit 233. The 3 marks in the graph represent 3 measurers. The horizontal axis represents the known hardness (no unit) measured by a durometer, and the vertical axis represents the estimated hardness (V) obtained by the method of fig. 9 by an electric durometer. From the graph, a polynomial fit is performed on data points of the estimated hardness and the known hardness, and a curve representing the relationship between the two is obtained. When the estimated hardness is measured by an electric durometer, the hardness can be converted into a known hardness by substituting the estimated hardness into a curve.

Returning to fig. 1, the storage unit 24 is a unit that stores various information, and is implemented by, for example, a RAM (Random Access Memory ), a ROM (Read Only Memory), an HDD (HARD DISK DRIVE ), or the like. The storage unit 24 stores therein a voltage-pressure conversion coefficient C _mp calculated by an experiment. The sound generation unit 25 is a unit that generates sound, and is realized by a speaker, for example. The sound generation unit 25 generates a beep sound at the start and end of measurement by the measuring device 1, for example. The display unit 26 is a unit that performs various displays, and is implemented by an LCD (Liquid CRYSTAL DISPLAY: liquid crystal display) or a CRT (Cathode Ray Tube Display: cathode ray tube display), for example. The display unit 26 displays various waveforms, hardness of the object (for example, at least one of elasticity information and viscosity information), and an indicator (indicator) for visualizing the hardness of the object.

The display unit 26 displays the estimated hardness obtained by the hardness estimating unit 234. As will be described later, the estimated hardness may be displayed on the surface of the living body at a measurement position by means of a color map (color map). As described later, the measurement position on the surface of the living body is estimated by the position estimating unit 236 from magnetic field data obtained from the position measuring device and capable of reflecting the position information. In some cases, the estimated hardness varies with the compression strength, and the estimated hardness varies with the depth from the surface of the living body.

The display unit 26 further includes a compression instruction unit 261 for providing an instruction of a compression method to the operator based on the result of the abnormal waveform detection unit 232. When the abnormal waveform detecting unit 232 detects that the compression strength is not suitable, the compression instructing unit 261 instructs the operator of the suitable compression strength. When the hardness estimation unit 234 designates a direct current component or an alternating current component as shown in fig. 8 and 9, an appropriate compression strength is instructed to the operator.

The power supply unit 27 is a power supply unit of the hardness calculation device 2. The input section 28 is a unit for a user to operate to input various information, and is implemented by a keyboard, a mouse, or the like, for example.

Returning to fig. 2 and 3, the main body portion 14 includes the receiving coil 11, a coil circuit board 110 for mounting the receiving coil 11, a battery 16, an operation button 140 for operation at the start of hardness calculation or the like, the motor 17, and an operation circuit board 141 connected to the receiving coil 11 and the transmitting coil 12. The movable portion 15 includes the transmitting coil 12 and a coil circuit board 120 for mounting the transmitting coil 12. Between the coil circuit board 110 and the coil circuit board 120, 1 or more springs 13 are arranged.

In the measuring device 1, when the rotational movement is generated by the motor 17, the shaft mounted at a position offset from the shaft of the motor 17 rotates, and the up-and-down movable portion 18 moves up and down (crank mechanism) accordingly. The motor 17 starts rotating when the operation button 140 is pressed, and the motor 17 stops rotating when the operation button 140 is released. By this up-and-down movement, the movable portion 15 periodically presses the measurement object. When the movable portion 15 presses the object to recess the object, the spring 13 contracts, the transmitting coil 12 and the receiving coil 11 approach each other, the magnitude of the magnetic field detected by the receiving coil 11 increases, and the receiving coil 11 can output information of a voltage corresponding to the magnitude of the reaction force generated by the contact portion 20.

As described above, the motor 17 stops rotating as the operation button 140 is released, so the stop position of the contact portion 20 is different depending on the timing at which the operator releases the operation button 140. For this purpose, the rotational position of the motor 17 is measured by an optical sensor, and the contact portion 20 is controlled to be always stopped at a fixed position. Thus, the measuring device 1 has the same hardware configuration as the durometer, and the dc component of the waveform is the same as the output value of the durometer. Thus, the biological sclerometer 1000 includes the function of a durometer.

< Execution order of hardness estimation application >

Next, the processing of the biological hardness tester 1000 will be described with reference to the flowchart of fig. 11 (with reference to other figures as appropriate). Hereinafter, a human body will be described as an example of a measurement object. First, a subject to be measured for body hardness is registered by an operator (step S1). The contents of registration are subject ID, subject name, sex, age, disease information, treatment information, measurement results of other examination apparatuses, and the like.

Fig. 12 shows an example of a registration screen.

Next, hardness measurement of the human body was performed by a durometer. Specifically, the operator presses the operation button 140 of the measuring device 1, and the motor 17 starts to operate, and starts to record data of the magnetic sensor (step S2). The measuring device 1 is here integrally mounted on an electric motor 17. In the case of this configuration, by driving the motor 17, the movable unit 15 can continuously press the object at the predetermined frequency fHz. For example, f=2 to 8Hz may be set. The microprocessor 23 of the hardness calculation device 2 acquires information from the measurement device 1 every time the movable portion 15 of the measurement device 1 presses the measurement object 150.

The operator gradually increases the pressing of the measuring device 1 in such a manner as to vertically contact the surface of the human body while keeping the operation button 140 pressed (step S3). Here, when the waveform of the measured magnetic sensor is abnormal, for example, when the pressing intensity is too strong or too weak, or when the measured waveform is inclined rather than being perpendicular to the human body surface, the microprocessor 23 detects the abnormal waveform (step S4). This determination can be made, for example, based on the voltage of the dc component, the frequency of the ac component, and the like of the magnetic sensor output voltage shown in fig. 8. This processing is executed by the judgment section 235 of the microprocessor 23. If yes, the process proceeds to step S5, and if no, the process proceeds to step S6. If it is determined that the waveform is abnormal, the microprocessor 23 displays a re-measurement message on the display unit 26, thereby prompting the operator to correct the compression method to an appropriate compression method (step S5).

If it is determined in step S4 that the waveform is not an abnormal waveform, the hardness is estimated (step S6). The microprocessor 23 determines whether or not these values are abnormal values based on the estimated values calculated in step S3 (step S7). This processing is executed by the judgment section 235 of the microprocessor 23. If yes, the process proceeds to step S5, and if no, the process proceeds to step S8. The determination of whether or not the abnormal value is present is performed by, for example, comparing the average value and the variance with a predetermined threshold value.

If no in step S7, the calculated hardness is stored as a measured value (step S8). The processing from step S2 to step S8 is repeatedly executed at a plurality of measurement points as necessary (step S9). After the measurement of all the measurement points is completed, the microprocessor 23 displays a drawing (mapping) of information on hardness or hardness onto a human body schematic diagram on the display section 26 (step S10).

Fig. 13 shows an example of this screen. In the example of fig. 13 (a), the hardness profile shows the hardness of 9 measurement points of the human body. The hardness can be expressed in terms of shade or color. Further, as shown in fig. 13 (b), the hardness of the sliding bar 1300 can be displayed at different depths. Further, in order to evaluate the therapeutic effect of acupuncture, massage, etc., the hardness and hardness profile of the past can be compared (step S11).

In this way, the hardness value of a certain portion can be displayed or compared with the previous value. Further, a hardness profile including the hardness of a plurality of measurement sites may be displayed or compared with a conventional hardness profile. In addition, the hardness at different depths can also be measured in the measurement method of the present embodiment.

For measuring the hardness at different depths, for example, in the data of fig. 6, the ac component FAC 1at the time when the dc component is large and the ac component FAC2 at the time when the dc component is small are acquired, and the corresponding hardness is obtained. The ac component FAC 1at the time when the dc component is large reflects the hardness of the deep portion, and the ac component FAC2 at the time when the dc component is small reflects the hardness of the shallow portion. As described above, the graph of fig. 6 is based on the assumption that the hardness is uniform, and therefore the size of the ac component is the same in any part. However, when the hardness varies with the depth, the magnitude of the ac component varies with the magnitude of the dc component.

In addition, in the case of using the magnetic sensor output as it is as shown in fig. 8 and 9, the hardness at a plurality of depths can be measured by taking a plurality of fixed points.

Fig. 14A and B are table diagrams showing correspondence tables included in the database 1001 of the embodiment.

Fig. 14A is an example of a correspondence table in which the waveform of the output voltage of the magnetic sensor 19 is converted into a pressure waveform and the hardness is converted from the pressure waveform as shown in fig. 6. Fig. 14A (a) is a table showing the correspondence between dc component amplitude and depth. Fig. 14A (b) is a table showing the correspondence between the amplitude and hardness of the ac component. These tables may be obtained by, for example, experiments in advance. When it is desired to measure the hardness at an arbitrary depth, the dc component amplitude corresponding to the depth is obtained by fig. 14A (a), and the ac component amplitude at the time of the dc component amplitude is obtained. Then, the hardness corresponding to the amplitude of the ac component is obtained by fig. 14A (b).

Fig. 14B is an example of a correspondence table in the case where the hardness is estimated using the output voltage of the magnetic sensor as it is as the force sensor as shown in fig. 8. In the example of fig. 8, the estimated hardness is calculated as an ac component V _AC of the voltage when the dc component V _D of the voltage is fixed to a constant value V _DC. In this case, the correspondence between the amplitude and the hardness of the ac component varies with the size of the dc component, that is, with the depth, and therefore, a plurality of correspondence tables are required according to the depth. Fig. 14B (a) is a table showing the amplitude and hardness of the ac component in the shallow portion (the dc component has a magnitude of 100 mV), and fig. 14B (B) is a table showing the amplitude and hardness of the ac component in the deep portion (the dc component has a magnitude of 200 mV).

In addition, in the case of estimating the hardness based on the dc component when the ac component is fixed as shown in fig. 9, it is necessary to prepare a plurality of correspondence tables of the dc component and the hardness in correspondence with a plurality of ac components. Here, the hardness in the correspondence table may be an estimated hardness, or may be a value obtained by converting the estimated hardness into a known hardness as described in fig. 10.

Fig. 15 shows an example of a screen displayed by comparing past data with latest data. The hardness information and the hardness distribution map may be displayed in a row, or the difference between them may be displayed. Through the above processing, all steps are ended.

< Estimation of measurement position >

Next, a method for obtaining measurement position information required for displaying the estimated hardness map on the display unit 26 will be described. The position measuring device 3 shown in fig. 1 includes, for example, 5 transmitting coils 302 and a three-axis receiving coil 301.

Fig. 16 is a schematic configuration diagram of 5 transmitting coils 302 and a three-axis receiving coil 301. Although the number of the transmitting coils 302 is 5 here, the number may be any number as long as the number is required to obtain the target position information. The triaxial receiving coil 301 is mounted inside the biological sclerometer 1000. The positional relationship between the 5 transmitting coils 302 and the measurement object is known. The transmitting coil 302 is located on a sample stage on which the measurement object 150 is disposed, for example. In the case where the measurement object 150 is a human body, it may be built in a bed or the like. This enables estimation of the measurement position of the living body durometer with respect to the transmitting coil.

The measuring principle of the position measuring device 3 is the same as that of the measuring device 1. A current is caused to flow through the transmitting coil 302 by the position estimation driving circuit 29, a magnetic field is generated around the transmitting coil, and a voltage is generated by the magnetic field in the triaxial receiving coil 301 according to the principle of electromagnetic induction. Unlike the measuring device 1, there are a plurality of receiving coils and oscillating coils, and interference of magnetic fields becomes a problem. This problem is solved by employing a time division method in which the flow and detection of current are switched using each combination (15 combinations) of the transmitting coil and the receiving coil in a short time. As another method, when a plurality of transmitting coils simultaneously flow current, the magnetic fields of the plurality of transmitting coils can be detected without interfering with each other by changing the frequency of the transmitting coils.

The position estimating unit 236 calculates position information required for displaying the estimated hardness map on the surface of the living body on the display unit 26. From the obtained magnetic field data, the three-dimensional position (horizontal direction X, Y, vertical direction Z) and attitude angle (elevation angle θ, azimuth angle Φ) of the triaxial receiving coil are estimated by performing simulation of the magnetic field. In the case of displaying on the display unit 26, for example, when displaying on a schematic view mapped to the back of the human body, it is only necessary to display the estimated hardness in the form of a color map by using only the positional information in the horizontal direction X, Y. In addition, when the map is displayed on the face surface in three dimensions, map display may be performed using position information X, Y, Z.

The present embodiment uses a magnetic field measurement method for estimating the position, but other methods may be used, such as estimating the measurement position by a camera. The measurement position may be estimated by performing second-order integration on the acceleration sensor.

With the present embodiment described above, it is possible to provide a hardness estimation unit in a hardness meter including a main body including a movable portion that can be continuously pressed against a measurement object, a pressure sensor for outputting reaction force information corresponding to a reaction force of a portion of the measurement object that is in contact with the movable portion, a motor for driving the main body and the movable portion by the motor, and a crank mechanism for causing the main body and the movable portion to perform piston movement, the hardness estimation unit estimating hardness based on an alternating current component of a pressure sensor value generated by the piston movement of the movable portion.

In the present embodiment, a magnetic sensor is used as the pressure sensor, but other types of sensors may be used. For example, a piezoresistive pressure sensor using a semiconductor process can be configured instead of the magnetic sensor 19 of fig. 2. The piezoresistive pressure sensor has a semiconductor strain gauge formed on the surface of a diaphragm (diaphragm), and the diaphragm is deformed by an external force (pressure) to generate a piezoresistive effect, thereby causing a resistance change, and converting such a resistance change into an electrical signal. Therefore, the force information shown in fig. 6 can be obtained directly from the output of the sensor.

The present invention is not limited to the above-described embodiments, and includes various modifications. The above embodiments are described in detail for easy understanding of the present invention, but are not limited to the configuration in which all the described structures are necessarily included. Some of the structures of one embodiment can be replaced with structures of other embodiments. In addition, the structure of other embodiments can be added to the structure of one embodiment. Other structures may be added, deleted, or replaced for a part of the structures of the embodiments.

Some or all of the various processes of the microprocessor 23 may be realized by hardware, for example, by performing integrated circuit design or the like. The above-described structures, functions, and the like may be implemented in software by a processor interpreting and executing a program for realizing the functions. Information such as programs, tables, and files for realizing the respective functions can be stored in a recording device such as a memory, a hard disk, and an SSD (Solid state disk), or a recording medium such as an IC card, an SD card, and a DVD.

In the above embodiments, the control lines and the information lines represent the portions necessary for the description, and not necessarily represent all the control lines and the information lines on the product. All structures can also be considered to be connected to each other.

Industrial applicability

The present invention can be used in a durometer for estimating the hardness of an object.

Description of the reference numerals

1 … Measuring device

2 … Hardness calculating device

11 … Receiving coil

12 … Transmitting coil

13 … Spring

14 … Main body portion

15 … Moving part

16 … Battery

17 … Motor

18 … Up-and-down movable part

19 … Magnetic sensor

20 … Contact portion

21 … Drive circuit

23 … Microprocessor

24 … Storage portion

25 … Sound generating part

26 … Display portion

27 … Power supply portion

28 … Input section

3 … Position measuring device

31 … Ac oscillation source

32 … Amplifier

33 … Preamplifier

34 … Wave detection circuit

35 … Reference signal

36 … Low pass filter

37 (A) … spring

37 (B) … buffer

110. 120 … Coil circuit board

140 … Working button

141 … Working circuit board

130 … Working circuit board

140 … Working button

231 … Voltage waveform generation part

232 … Abnormal waveform detection unit

233 … Voltage-pressure conversion unit

234 … Hardness estimation portion

235 … Determination part

236 … Position estimating unit

261 … Compression indication part

301 … Triaxial receiving coil

302 … Transmitting coil

1000 … Organism sclerometer

Claims

1. A hardness tester, which comprises a hardness tester, characterized by comprising the following steps:

a movable part that can be continuously pressed against a measurement object;

a sensor that outputs an output signal reflecting a reaction force of a portion of the object to be measured that is in contact with the movable portion;

A power mechanism connected to the movable portion via an elastic body, for moving the movable portion in a piston manner; and

A hardness estimating unit that estimates the hardness of the measurement object based on the output signal generated by the piston movement of the movable unit,

The hardness estimating unit estimates the hardness of the object to be measured based on the amplitude of the AC component when the magnitude of the DC component of the output signal is fixed to a predetermined value, or

The hardness of the object to be measured is estimated based on the magnitude of the DC component when the amplitude of the AC component of the output signal is fixed to a predetermined value.

2. The durometer of claim 1, wherein:

Comprises an abnormal waveform detection unit for detecting abnormal waveform on condition that the magnitude of the DC component of the output signal does not fall within a certain range,

The hardness estimation unit estimates the hardness of the measurement object in a range in which the abnormal waveform detection unit does not detect an abnormal waveform.

3. The durometer of claim 1, wherein:

comprises an abnormal waveform detection unit for detecting abnormal waveform on condition that upper limit and lower limit of AC component of the output signal can not be detected,

4. The durometer of claim 1, wherein:

The sensor includes a voltage-pressure conversion unit that converts an output voltage of the sensor into pressure information.

5. The durometer of claim 1, comprising:

A position estimating unit for estimating a measurement position of the durometer; and

And a hardness distribution map display unit for displaying the calculated hardness as a distribution map using the measurement position.

6. The durometer of claim 5, comprising:

The hardness profile display section displays a difference between the two hardness profiles.

7. A method of hardness measurement, comprising:

A first step of vibrating the movable part;

A second step of acquiring a sensing signal due to a reaction force from the measurement object when the movable portion is brought into contact with the measurement object;

A third step of acquiring an ac component of the sensing signal; and

A fourth step of estimating the hardness of the measurement object, wherein,

In the first step, a vibration member for vibrating the movable portion is used, the vibration member being connected to the movable portion via an elastic body,

In the fourth step, the hardness of the measurement object is estimated based on the amplitude of the ac component when the magnitude of the dc component of the sensing signal is fixed to a predetermined value, or

The hardness of the object to be measured is estimated based on the magnitude of the DC component when the amplitude of the AC component of the sensing signal is fixed to a predetermined value.

8. The hardness measurement method according to claim 7, wherein:

A computer device including a microprocessor, a storage portion, an input portion, and an output portion is used,

The microprocessor converts the waveform of the magnetic sensor signal obtained from the input unit into a waveform of pressure by performing voltage-pressure conversion, thereby obtaining the sensing signal.

9. The hardness measurement method according to claim 7, wherein:

The microprocessor uses the waveform of the magnetic sensor signal directly as the sensing signal.

10. The hardness measurement method according to claim 8 or 9, characterized in that:

A corresponding table of the amplitude and hardness of the sensing signal is prepared as a database in the storage portion,

The correspondence table indicates the correspondence between the amplitude and the hardness of the alternating current component of the sensing signal in the case where the direct current component of the sensing signal is fixed, or

The correspondence between the amplitude and the hardness of the DC component of the sensing signal when the AC component of the sensing signal is fixed is shown,

The microprocessor estimates the hardness based on the correspondence table.